Research overview: loss of sweet-taste perception in felids

Cats are famously indifferent to sweetness, and genetics revealed why: they carry a pseudogenized sweet-taste receptor gene that no longer produces a functional receptor. This overview surveys the discovery that the Tas1r2 gene is disabled in the domestic cat and across the cat family, the inference that this loss accompanied the lineage's commitment to a meat diet in which detecting sugars conferred little advantage, and the broader pattern of taste-receptor evolution in carnivores. It discusses how this single example connects sensory biology, diet, and molecular evolution, and how taste-gene losses serve as genomic fingerprints of dietary specialization across mammals.